Construction method and construction system for eliminating sand liquefaction

ABSTRACT

Disclosed are a construction method and a construction system for eliminating sand liquefaction. The construction system includes a first drilling rod, a pneumatic down-the-hole (DTH) hammer installed on the first drilling rod, an air compressor drivingly connected with the pneumatic DTH hammer, a driving motor drivingly connected with the first drilling rod and a high-pressure pump connected with the first drilling rod; and the construction method includes following steps: measuring the ground to be constructed to determine the pile position to be constructed; controlling the air compressor to drive the pneumatic DTH hammer to drill holes in the pile position to be constructed, controlling the driving motor to drive the first drilling rod to rotate around an axis in an up-down direction, and controlling the high-pressure pump to spray the cement slurry toward a circumferential side of the first drilling rod.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to Chinese Patent Application No. 202110965150.6, filed on Aug. 20, 2021, the contents of which are hereby incorporated by reference.

TECHNICAL FIELD

The present application relates to the technical field of composite foundation, and in particular to a construction method and a construction system for eliminating sand liquefaction.

BACKGROUND

Sand liquefaction may occur in sand layers when a building composite foundation is adopted under a conventional construction method, which will result in a poor bearing capacity of the constructed foundation; such problem is generally tackled, in existing construction methods, by adopting vibro-replacement stone columns with an unpleasant result of leaving large amounts of construction waste such as slurry after construction, which is far from meeting the construction requirements and causes high costs of removing construction waste and complicated and troublesome operations.

SUMMARY

With objective of solving the problem of difficulty in eliminating sand liquefaction, the present application provides a construction method and a construction system for eliminating sand liquefaction.

In order to achieve the above objective, the present application provides a construction method and a construction system for eliminating sand liquefaction, where the construction system includes a first drilling rod, a pneumatic down-the-hole (DTH) hammer installed at one end of the first drilling rod, an air compressor drivingly connected with the pneumatic DTH hammer, a driving motor drivingly connected with the first drilling rod, and a high-pressure pump connected with the first drilling rod to spray cement slurry toward a periphery side of the first drilling rod; and

the construction method for eliminating sand liquefaction includes the following steps:

measuring a ground to be constructed to determine a pile position to be constructed;

controlling the air compressor to drive the pneumatic DTH hammer to drill hole in the pile position to be constructed, controlling the driving motor to drive the first drilling rod to rotate around an axis in an up-down direction, and controlling the high-pressure pump to spray the cement slurry toward the circumferential side of the first drilling rod;

acquiring a depth of a drilled hole drilled by the first drilling rod; and

raising the first drilling rod to a ground surface when the depth of the drilled hole reaches a designed depth.

Optionally, after acquiring the depth of the drilled hole drilled by the first drilling rod, the method further comprises:

controlling the air compressor to output a safe air pressure to drive the pneumatic DTH hammer to drill through the safe air pressure before the drilled hole reaches a safe depth; and

controlling the high-pressure pump to output a safe slurry pressure so as to spray the cement slurry through the safe slurry pressure;

among them, the safe depth is smaller than the designed depth.

Optionally, after acquiring the depth of the drilled hole drilled by the first drilling rod, the method further includes:

controlling the air compressor to output a first air pressure to drive the pneumatic DTH hammer to drill through the first air pressure when the depth of the drilled hole reaches the safe depth; and

controlling the high-pressure pump to output a first slurry pressure to spray the cement slurry through the first slurry pressure;

among them, the first air pressure is greater than the safe air pressure, and the first slurry pressure is greater than the safe slurry pressure.

Optionally, raising the first drilling rod to the ground surface when the depth of the drilled hole reaches the designed depth is achieved as follows:

controlling the air compressor to output a second air pressure to drive the pneumatic DTH hammer to vibrate through the second air pressure; and

controlling the high-pressure pump to output a second slurry pressure to spray the cement slurry through the second slurry pressure;

among them, the second air pressure is greater than the first air pressure, and the second slurry pressure is greater than the first slurry pressure.

Optionally, the construction system further comprises a second drilling rod with a length greater than that of the first drilling rod.

Optionally, the controlling the air compressor to drive the pneumatic DTH hammer to drill hole in the pile position to be constructed, controlling the driving motor to drive the first drilling rod to rotate around an axis in an up-down direction, and controlling the high-pressure pump to spray the cement slurry toward the circumferential side of the first drilling rod further includes:

controlling the driving motor, the air compressor and the high-pressure pump to stop working when the first drilling rod completely extends into the drilled hole;

extending the first drilling rod to obtain the second drilling rod; and

controlling the driving motor, the air compressor and the high-pressure pump to start working to drive the second drilling rod to continue drilling.

Optionally, the construction system further comprises a first stiffening core and an elevator for placing the first stiffening core; and

after raising the first drilling rod to a ground surface when the depth of the drilled hole reaches a designed depth, the method also includes:

controlling the elevator to place the first stiffening core into the drilled hole.

Optionally, the first stiffening core is provided with at least three centering brackets towards a side wall of the drilled hole;

the controlling the elevator to place the first stiffening core into the drilled hole includes:

connecting the first stiffening core with the elevator;

extending the first stiffening core into the drilled hole, and enabling a plurality of centering brackets on the first stiffening core to abut against an inner wall of the drilled hole respectively; and

controlling the elevator to extend the first stiffening core to the designed depth.

Optionally, the construction system further includes a second stiffening core with a length greater than that of the first stiffening core; and

the controlling the elevator to place the first stiffening core into the drilled hole further includes:

controlling the elevator to stop working when the first stiffening core completely extends into the drilled hole;

extending the first stiffening core to obtain the second stiffening core; and

controlling the elevator to start working so as to continuously place the second stiffening core.

The present application also provides a construction system, which includes:

a main driller, including a first drilling rod and a pneumatic DTH hammer installed at one end of the first drilling rod;

an air compressor connected with the pneumatic DTH hammer in a driving way and used for driving the pneumatic DTH hammer to vibrate and drill;

a high-pressure pump connected with the first drilling rod, where the high-pressure pump is used for injecting cement slurry towards a circumferential side of the first drilling rod;

a driving motor installed on the main driller, where the driving motor is connected with the first drilling rod in a driving way to drive the first drilling rod to rotate around an axis in an up-down direction; and

a controlling device electrically connected with the air compressor, the high-pressure pump and the driving motor respectively, where the controlling device includes a memory, a processor and a controlling program stored in the memory and operable on the processor, and the controlling program is configured to realize the construction method for eliminating sand liquefaction as described above.

Optionally, the construction system further comprises a first stiffening core and an elevator, and the elevator is used for placing the first stiffening core into a drilled hole.

The construction method for eliminating sand liquefaction includes the following steps:

measuring a ground to be constructed to determine a pile position to be constructed;

controlling the air compressor to drive the pneumatic DTH hammer to drill hole in the pile position to be constructed, controlling the driving motor to drive the first drilling rod to rotate around an axis in an up-down direction, and controlling the high-pressure pump to spray the cement slurry toward the circumferential side of the first drilling rod; acquiring a depth of a drilled hole drilled by the first drilling rod; and

raising the first drilling rod to a ground surface when the depth of the drilled hole reaches a designed depth.

According to the technical scheme of the present application, the air compressor drives the pneumatic DTH hammer to vibrate to break up the gravel, and the high-pressure pump sprays high-pressure cement slurry towards the periphery side of the first drilling rod, where the cement slurry can not only cut the sand layer, but also allows sand and gravel to be fully mixed with the cement slurry; the first drilling rod rotates under the driving of the driving motor, thereby driving the high-pressure pump to rotate and spray the cement slurry, thus further stirring the cement slurry and the sand and gravel; the first drilling rod is, as reaching the designed depth, raised while rotating and the cement slurry is continuously sprayed, so that the cement slurry and the sand and gravel are fully stirred; and the cement slurry is allowed to be solidified after the first drilling rod is raised to the surface; by doing so, sand liquefaction is eliminated while constructing the composite foundation, and very little construction waste is produced in the manufacturing process.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly explain the embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings could be obtained according to the structures shown in these drawings without any creative effort.

FIG. 1 shows a structural schematic diagram of an embodiment of a construction system provided by the present application.

FIG. 2 illustrates a structural schematic diagram of a controlling device of a hardware running environment related to the embodiment scheme in FIG. 1 .

FIG. 3 shows a processing of an embodiment of the construction method for eliminating sand liquefaction provided by the present application.

FIG. 4 shows a schematic diagram of a process of obtaining the depth of a hole drilled by the first drilling rod when the depth of the drilled hole does not reach a safe depth in this application.

FIG. 5 illustrates a flow of obtaining the depth of the hole drilled by the first drilling rod when the depth of the drilled hole reaches a safe depth in this application.

FIG. 6 illustrates a flow of raising the first drilling rod to the surface when the depth of the drilled hole reaches a designed depth in this application.

FIG. 7 shows a flow of controlling the air compressor to drive the pneumatic DTH hammer to drill holes in the pile position to be constructed, controlling the driving motor to drive the first drilling rod to rotate around an axis in an up-down direction, and controlling the high-pressure pump to spray the cement slurry toward a circumferential side of the first drilling rod in this application.

FIG. 8 shows a schematic diagram of a first flow in this application of controlling the elevator to place the first stiffening core into the drilled hole.

FIG. 9 shows a schematic diagram of a second flow in this application of controlling the elevator to place the first stiffening core into the drilled hole.

The realization, functional characteristics and advantages of the present application will be further explained with reference to the attached drawings in combination with the embodiments.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, but not all of them. Based on the embodiments of the present application, all other embodiments obtained by ordinary technicians in the field without creative labor are within the protection scope of the present application.

It should be noted that, if directional indication is involved in the embodiment of the present application, the directional indication is only used to explain the relative positional relationship, movement situation, etc. between components in a specific posture, and if the specific posture changes, the directional indication will also change accordingly.

In addition, if there are descriptions related to “first” and “second” in the embodiment of the present application, the descriptions of “first” and “second” are only used for descriptive purposes, and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of indicated technical features. Therefore, the features defined with “first” and “second” can include at least one of these features explicitly or implicitly. In addition, the technical solutions of various embodiments can be combined with each other, but it must be based on the realization of ordinary technicians in this field. When the combination of technical solutions is contradictory or impossible to realize, it should be considered that the combination of such technical solutions does not exist and is not within the scope of protection required by the present application.

Sand liquefaction may occur in sand layers as building composite foundation with conventional construction method, resulting a poor bearing capacity of the foundation; such problem is generally tackled, in existing construction methods, by adopting vibro-replacement stone columns with an unpleasant result of leaving large amounts of construction waste such as slurry after construction, which is far from meeting construction requirements for causing high costs of removing construction waste and complicated and troublesome operations.

Referring to FIG. 1 , the present application provides a construction system 100, where the construction system 100 includes a main driller, an air compressor 20, a high-pressure pump 30, a driving motor 40 and a controlling device 10; the main driller includes a first drilling rod 50 and a pneumatic down-the-hole (DTH) hammer 60 installed at one end of the first drilling rod 5; the air compressor 20 is drivingly connected with the pneumatic DTH hammer 60 and used for driving the pneumatic DTH hammer 60 to vibrate and drill; the high-pressure pump 30 is connected with the first drilling rod 50 and used for injecting cement slurry toward the circumferential side of the first drilling rod 50; the driving motor 40 is installed on the main body drilling machine and connected with the first drilling rod 50 in a driving way to drive the first drilling rod 50 to rotate around an axis in an up-down direction; the controlling device 10 is electrically connected with the air compressor 20, the high-pressure pump 30 and the driving motor 40, respectively, and includes a memory, a processor and a controlling program stored in the memory and operable on the processor, where the controlling program is configured to realize a construction method of eliminating sand liquefaction by the construction system 100.

Referring to FIG. 2 , the controlling device 10 includes a processor 1001, a CPU for instance, a communication bus 1002, a user interface 1003, a network interface 1004, and a memory 1005; among them, the communication bus 1002 is used to realize the connection and communication between these components; the user interface 1003 includes a display and an input unit such as a keyboard, and the user interface 1003 optionally includes a standard wired interface and a wireless interface; the network interface 1004 optionally includes a standard wired interface and a wireless interface (such as a wireless fidelity (WI-FI) interface); and the memory 1005 is a high-speed random access memory (RAM) or a non-volatile memory, such as a disk memory, or the memory 1005 is alternatively a storage device independent of the aforementioned processor 1001.

It can be understood by those skilled in the art that the structure of the controlling device 10 as shown in FIG. 2 does not constitute a limitation on the controlling device 10, and may include more or less components than those shown, or combine some components, or different component arrangements.

As shown in FIG. 2 , the memory 1005, which is a computer storage medium, includes an operating system, a network communication module, a user interface module, and a controlling program of the construction method of the construction system 100 to eliminate sand liquefaction.

In the controlling device 10 as shown in FIG. 2 , the processor 1001 calls the controlling program of the construction method for eliminating sand liquefaction of the construction system 100 stored in the memory 1005, and performs the following operations:

measuring a ground to be constructed to determine a pile position to be constructed;

controlling the air compressor 20 to drive the pneumatic DTH hammer 60 to drill hole in the pile position to be constructed, controlling the driving motor 40 to drive the first drilling rod 50 to rotate around an axis in an up-down direction, and controlling the high-pressure pump 30 to spray the cement slurry toward the circumferential side of the first drilling rod 50;

acquiring a depth of a drilled hole drilled by the first drilling rod 50; and

raising the first drilling rod 50 to a ground surface when the depth of the drilled hole reaches a designed depth;

further, the processor 1001, in addition to call the controlling program of the construction method for eliminating sand liquefaction of the construction system 100 stored in the memory 1005, also performs the following operations:

controlling the air compressor 20 to output a safe air pressure to drive the pneumatic DTH hammer 60 to drill through the safe air pressure when the depth of the drilled hole does not reach a safe depth; and

controlling the high-pressure pump 30 to output a safe slurry pressure to inject the cement slurry through the safe slurry pressure;

among them, the safe depth is smaller than the designed depth.

Further, the processor 1001, in addition to calling the controlling program of the construction method for eliminating sand liquefaction of the construction system 100 stored in the memory 1005, also performs the following operations:

controlling the air compressor 20 to output a first air pressure to drive the pneumatic DTH hammer 60 to drill through the first air pressure when the drilling depth reaches the safe depth; and

controlling the high-pressure pump 30 to output a first slurry pressure to inject the cement slurry through the first slurry pressure;

among them, the first air pressure is greater than the safe air pressure, and the first slurry pressure is greater than the safe slurry pressure.

Further, the processor 1001, in addition to calling the controlling program of the construction method for eliminating sand liquefaction of the construction system 100 stored in the memory 1005, also performs the following operations:

controlling the air compressor 20 to output a second air pressure to drive the pneumatic DTH hammer 60 to vibrate through the second air pressure; and

controlling the high-pressure pump 30 to output a second slurry pressure to inject the cement slurry through the second slurry pressure;

among them, the second air pressure is greater than the first air pressure, and the second slurry pressure is greater than the first slurry pressure.

Further, the processor 1001, in addition to calling the controlling program of the construction method for eliminating sand liquefaction of the construction system 100 stored in the memory 1005, also performs the following operations:

the step of controlling the air compressor 20 to drive the pneumatic DTH hammer 60 to drill a hole in the pile position to be constructed, controlling the driving motor 40 to drive the first drilling rod 50 to rotate around the axis in the up-down direction, and controlling the high-pressure pump 30 to spray the cement slurry toward the circumferential side of the first drilling rod 50 further includes:

controlling the driving motor 40, the air compressor 20 and the high-pressure pump 30 to stop working when the first drilling rod 50 fully extends into the drilled hole;

extending the first drilling rod 50 to obtain the second drilling rod; and

controlling the driving motor 40, the air compressor 20 and the high-pressure pump 30 to start working, so as to drive the second drilling rod to continue drilling.

Further, the processor 1001, in addition to calling the controlling program of the construction method for eliminating sand liquefaction of the construction system 100 stored in the memory 1005, also performs the following operations:

controlling the elevator to place a first stiffening core into the drilled hole.

Optionally, the first stiffening core is provided with at least three centering brackets towards the side wall of the drilled hole.

The step of controlling the elevator to place the first stiffening core into the drilled hole comprises:

connecting the first stiffening core with the elevator;

extending the first stiffening core into the drilled hole, and enabling a plurality of centering brackets on the first stiffening core to abut against the inner wall of the drilled hole respectively; and

controlling the elevator to extend the first stiffening core to the designed depth.

Further, the processor 1001, in addition to calling the controlling program of the construction method for eliminating sand liquefaction of the construction system 100 stored in the memory 1005, also performs the following operations:

controlling the elevator to stop working when the first stiffening core completely extends into the drilled hole;

extending the first stiffening core to obtain the second stiffening core; and

controlling the elevator to start working so as to continuously place the second stiffening core.

According to the technical scheme of the present application, the air compressor 20 drives the pneumatic DTH hammer 60 to vibrate to break up the gravel, and the high-pressure pump 30 sprays high-pressure cement slurry towards the periphery side of the first drilling rod 50, where the cement slurry can not only cuts the sand layer, but also allows sand and gravel to be fully mixed with the cement slurry; the first drilling rod 50 rotates under the driving of the driving motor 40, thereby driving the high-pressure pump 30 to rotate and spray the cement slurry, thus further stirring the cement slurry and the sand and gravel; the first drilling rod 50 is, as reaching the designed depth, raised while rotating and the cement slurry is continuously sprayed, so that the cement slurry and the sand and gravel are fully stirred; and the cement slurry is allowed to be solidified after the first drilling rod 50 is raised to the surface; by doing so, sand liquefaction is eliminated while constructing the composite foundation, and very little construction waste is produced in the manufacturing process.

The construction system 100 further includes an elevator for placing the first stiffening core into the drilled hole.

In this embodiment, the first stiffening core and the elevator for placing the first stiffening core are arranged for the first stiffening core may be required to be placed inside the drilled hole as applying the construction system, and the bearing strength of the foundation is therefore strengthened.

Referring to FIG. 3 , the present application proposes a construction method for eliminating sand liquefaction, where cement slurry is fully mixed with sand and gravel in the drilled hole so as to form a composite foundation directly after solidification; such method is simple with small workload.

As can be seen from FIG. 3 , a flowchart of an embodiment of the construction method for eliminating sand liquefaction provided in this embodiment, the construction method comprises:

S10, measuring a ground to be constructed to determine a pile position to be constructed;

S20, controlling the air compressor 20 to drive the pneumatic DTH hammer 60 to drill a hole in the pile position to be constructed, controlling the driving motor 40 to drive the first drilling rod 50 to rotate around an axis in an up-down direction, and controlling the high-pressure pump 30 to spray the cement slurry toward a circumferential side of the first drilling rod 50;

S30, obtaining a depth of the drill hole drilled by the first drilling rod 50; and

S40, raising the first drilling rod 50 to a ground surface when the depth of the drilled hole reaches the designed depth.

According to the technical scheme of the present application, the air compressor 20 drives the pneumatic DTH hammer 60 to vibrate to break up the gravel, and the high-pressure pump 30 sprays high-pressure cement slurry towards the periphery side of the first drilling rod 50, where the cement slurry can not only cuts the sand layer, but also allows sand and gravel to be fully mixed with the cement slurry; the first drilling rod 50 rotates under the driving of the driving motor 40, thereby driving the high-pressure pump 30 to rotate and spray the cement slurry, thus further stirring the cement slurry and the sand and gravel; the first drilling rod 50 is, as reaching the designed depth, raised while rotating and the cement slurry is continuously sprayed, so that the cement slurry and the sand and gravel are fully stirred; and the cement slurry is allowed to be solidified after the first drilling rod 50 is raised to the surface; by doing so, sand liquefaction is eliminated while constructing the composite foundation, and very little construction waste is produced in the manufacturing process.

The pneumatic DTH hammer 60 achieves the drilling by vibrating and crushing stones, and the high-pressure pump 30 sprays cement slurry toward the circumferential side of the first drilling rod 50, which may affect the construction workers on the ground; therefore, in this embodiment, after the step S30, the method as shown in FIG. 4 further comprises:

S311, controlling the air compressor 20 to output a safe air pressure to drive the pneumatic DTH hammer 60 to drill through the safe air pressure before the depth of the drilled hole reaches a safe depth; and

S312, controlling the high-pressure pump 30 to output a safe slurry pressure to inject the cement slurry through the safe slurry pressure, where the safe depth is smaller than the designed depth.

In this embodiment, the safe depth is a preset depth, the pneumatic DTH hammer 60 and the high-pressure pump 30 will affect the ground construction personnel before the depth of the frilled hole reaches the safe depth, so the relatively small safe air pressure and safe slurry pressure are adopted to reduce the interference to ground workers.

Besides, the drilling speed is slow when the safe air pressure and the safe slurry pressure are used all the time, and the drilling speed should be increased after ensuring a relatively small impact on the ground construction personnel; therefore, in this embodiment, after the step S30, the method as shown in FIG. 5 further comprises:

S321, controlling the air compressor 20 to output a first air pressure to drive the pneumatic DTH hammer 60 to drill through the first air pressure when the drilling depth reaches the safe depth; and

S322, controlling the high-pressure pump 30 to output a first slurry pressure to inject the cement slurry through the first slurry pressure, where the first air pressure is greater than the safe air pressure, and the first slurry pressure is greater than the safe slurry pressure.

In this embodiment, the drilling speed is slow when the safe air pressure and the safe slurry pressure are used all the time, and the drilling speed should be increased after ensuring a relatively small impact on the ground construction personnel; therefore, after the depth has reached the safe depth, the air compressor 20 increases the output air pressure to the first air pressure and the high-pressure pump 30 increases the output slurry pressure to the first slurry pressure, thus increasing the drilling speed and the construction efficiency.

The cement slurry and sand and gravel need to be fully stirred when the drilled hole reaches the designed depth, so the step S40 in this embodiment as shown in FIG. 6 further includes:

S41, controlling the air compressor 20 to output a second air pressure to drive the pneumatic DTH hammer 60 to vibrate through the second air pressure; and

S42, controlling the high-pressure pump 30 to output a second slurry pressure to spray the cement slurry through the second slurry pressure;

among them, the second air pressure is greater than the first air pressure, and the second slurry pressure is greater than the first slurry pressure.

In this embodiment, the second air pressure is greater than the first air pressure, and the second slurry pressure is greater than the first slurry pressure. A high-pressure cement slurry will enlarge the drilled hole, and the pneumatic DTH hammer 60 will increase the vibration so as to fully mix the cement slurry with sand and gravel, thus ensuring that sand and gravel will not accumulate while ensuring a high bearing capacity of the cement slurry after solidification.

In actual construction, one drill rod is not enough to drill to the designed depth, so it is necessary to extend the first drilling rod 50; the step S20 as shown in FIG. 7 in this embodiment therefore further comprises:

S21, controlling the driving motor 40, the air compressor 20 and the high-pressure pump 30 to stop working when the first drilling rod 50 fully extends into the drilled hole;

S22, extending the first drilling rod 50 to obtain the second drilling rod; and

S23, controlling the driving motor 40, the air compressor 20 and the high-pressure pump 30 to start working to drive the second drilling rod to continue drilling.

In this embodiment, the second drilling rod is the first drilling rod 50 after splicing, and the operation can be repeated and spliced again after the second drilling rod completely extends into the drilled hole by splicing again so as to continue drilling. It should be noted that when the first drilling rod 50 is spliced, the driving motor 40, the air compressor 20 and the high-pressure pump 30 should stop working to prevent accidents.

In some cases, it is necessary to add a stiffening core into the drilled hole to improve the bearing capacity of the single pile and thus the strength of the foundation; in this embodiment, after step S40, the method further comprises:

S41, controlling the elevator to place the first stiffening core into the drilled hole.

In this embodiment, the elevator places the first stiffening core connected with it into the drilled hole, so as to strengthen the foundation strength.

Furthermore, at least three centering brackets are arranged on the side wall of the first stiffening core facing the drilled hole, so that the core can be limited in the middle of the drilled hole when placing the first stiffening core; in this embodiment, the step S41 as shown in FIG. 8 includes:

S4111, connecting the first stiffening core with the elevator;

S4112, extending the first stiffening core into the drilled hole, and making a plurality of centering brackets on the first stiffening core abut against the inner wall of the drilled hole respectively; and

S4113, controlling the elevator to extend the first stiffening core to the designed depth.

In this embodiment, as the elevator places the first stiffening core into the drilled hole, care is taken that the centering brackets are each against the inner wall of the drilled hole, thus ensuring that the first stiffening core is positioned in the middle of the drilled hole, and it should be noted that at least three centering brackets on the first stiffening core are required to limit the first stiffening core in the middle of the drilled hole.

In actual construction, one drill rod is not enough to drill to the designed depth, so it is necessary to extend the first drilling rod; the construction system 100 further includes a second stiffening core with a length greater than that of the first stiffening core; the step S41 as shown in FIG. 9 in this embodiment therefore further comprises:

S4121, controlling the elevator to stop working when the first stiffening core fully extends into the drilled hole;

S4122, extending the first stiffening core to obtain the second stiffening core; and

S4123, controlling the elevator to start working so as to continuously place the second stiffening core.

In this embodiment, the second stiffening core is the first stiffening core after splicing, the operation can be repeated after the second stiffening core completely extends into the drilled hole by splicing again so as to continue placing the core; and it should be noted that the working should be stopped when placing the first stiffening core so as to prevent accidents.

The above is only an optional embodiment of the present application, which does not limit the patent scope of the present application. All equivalent structural changes made by using the contents of the present specification and drawings, or direct/indirect application in other related technical fields under the inventive concept of the present application are included in the patent protection scope of the present application. 

What is claimed is:
 1. A construction method for eliminating sand liquefaction, applied to a construction system, wherein the construction system comprises a first drilling rod, a pneumatic down-the-hole (DTH) hammer installed at one end of the first drilling rod, an air compressor drivingly connected with the pneumatic DTH hammer, a driving motor drivingly connected with the first drilling rod, and a high-pressure pump connected with the first drilling rod to spray cement slurry toward a periphery of the first drilling rod; wherein the construction method for eliminating sand liquefaction comprises the following steps: measuring a ground to be constructed to determine a pile position to be constructed; controlling the air compressor to drive the pneumatic DTH hammer to drill holes in the pile position to be constructed, controlling the driving motor to drive the first drilling rod to rotate around an axis in an up-down direction, and controlling the high-pressure pump to spray the cement slurry toward a circumferential side of the first drilling rod; acquiring a depth of a drilled hole drilled by the first drilling rod; and raising the first drilling rod to a ground surface then the depth of the drilled hole reaches a designed depth.
 2. The construction method according to claim 1, after the step of acquiring the depth of the hole drilled by the first drilling rod, further comprising: controlling the air compressor to output safe air pressure to drive the pneumatic DTH hammer to drill through the safe air pressure before the depth of the drilled hole reaches a safe depth; and controlling the high-pressure pump to output safe slurry pressure so as to spray the cement slurry through the safe slurry pressure; wherein the safe depth is smaller than the designed depth.
 3. The construction method according to claim 2, after the step of acquiring the depth of the hole drilled by the first drilling rod, further comprising: controlling the air compressor to output a first air pressure to drive the pneumatic DTH hammer to drill through the first air pressure when the depth of the drilled hole reaches the safe depth; and controlling the high-pressure pump to output a first slurry pressure to spray the cement slurry through the first slurry pressure; wherein the first air pressure is greater than the safe air pressure, and the first slurry pressure is greater than the safe slurry pressure.
 4. The construction method according to claim 3, wherein the step of raising the first drilling rod to the ground surface when the depth of the drilled hole reaches the designed depth comprises: controlling the air compressor to output a second air pressure to drive the pneumatic DTH hammer to vibrate through the second air pressure; and controlling the high-pressure pump to output a second slurry pressure to spray the cement slurry through the second slurry pressure; wherein the second air pressure is greater than the first air pressure, and the second slurry pressure is greater than the first slurry pressure.
 5. The construction method according to claim 1, wherein the construction system further comprises a second drilling rod with a length greater than that of the first drilling rod; the first drilling rod rotates around the axis in the up-down direction while the air compressor drives the pneumatic DTH hammer to drill holes in the pile position to be constructed, and the circumferential side of the first drilling rod is sprayed with cement slurry by the high-pressure pump; the second drilling rod is obtained by extending the first drilling rod when the first drilling rod is fully extended into the drilled hole, where the driving motor, the air compressor and the high pressure pump stop working when the first drilling rod is fully extended into the drilled hole; the driving motor, the air compressor and the high pressure pump start working to drive the second drilling rod to continue drilling after the second drilling rod is obtained.
 6. The construction method according to claim 1, wherein the construction system further comprises a first stiffening core and an elevator for placing the first stiffening core; after the step of raising the first drilling rod to the ground surface when the depth of the drilled hole reaches the designed depth, the method further comprises: controlling the elevator to place the first stiffening core into the drilled hole.
 7. The construction method according to claim 6, wherein the first stiffening core is provided with at least three centering brackets towards a side wall of the drilled hole; the step of controlling the elevator to place the first stiffening core into the drilled hole comprises: connecting the first stiffening core with the elevator; extending the first stiffening core into the drilled hole, and enabling a plurality of centering brackets on the first stiffening core to abut against the inner wall of the drilled hole; and controlling the elevator to extend the first stiffening core to the designed depth.
 8. The construction method according to claim 6, wherein the construction system further comprises a second stiffening core with a length greater than that of the first stiffening core; the step of controlling the elevator to place the first stiffening core into the drilled hole further comprises: controlling the elevator to stop working when the first stiffening core completely extends into the drilled hole; extending the first stiffening core to obtain the second stiffening core; and controlling the elevator to start working so as to continuously place the second stiffening core.
 9. A construction system, comprising: a main driller, comprising a first drilling rod and a pneumatic DTH hammer installed at one end of the first drilling rod; an air compressor connected with the pneumatic DTH hammer in a driving way and used for driving the pneumatic DTH hammer to vibrate and drill; a high-pressure pump connected with the first drilling rod used for injecting cement slurry towards a circumferential side of the first drilling rod; a driving motor installed on the main driller and connected with the first drilling rod in a driving way to drive the first drilling rod to rotate around an axis in an up-down direction; and a controlling device electrically connected with the air compressor, the high-pressure pump and the driving motor respectively, wherein the controlling device comprises a memory, a processor and a controlling program stored in the memory and operable on the processor, and the controlling program is configured to realize the construction method for eliminating sand liquefaction according to claim
 1. 10. The construction system according to claim 9, wherein the construction system further comprises a first stiffening core and an elevator, and the elevator is used for placing the first stiffening core into the drilled hole. 